Swing-type excavation machines, for example hydraulic excavators and front shovels, may be used for transferring material from a dig location to a dump location. These machines generally utilize one or more systems (consuming torque from a power source of the machine), requiring significant hydraulic pressure and flow for performing various operations (the one or more systems including an implement system, a swing system, etc.). For instance, the swing system may include power source-driven swing pump passing pressurized fluid through a swing motor to rotate an upper carriage of the machine relative to an undercarriage of the machine.
Such machines also include a control system that may be configured to determine the torques consumed (or drawn from the power source) by each of the one or more systems to efficiently control operation of the machine and/or the one or more systems of the machine. For certain systems, it may be possible to accurately determine the torque received from the engine. However, it may not be possible to accurately determine the torque consumed by the swing system.
In such situations, the control system may predict/estimate a value of torque consumed by the swing system. The prediction/estimation may not yield an accurate value of torque being consumed by the swing system. Accordingly, the control system may not able to accurately determine a total torque demand, which may lead to inefficient operation of the machine. Further, due to the inaccurate torque determination, in certain scenarios, the condition when the total torque demand exceeds the maximum torque that can be generated by the power source may not be detected. In such situations, the power source may stall.
U.S. patent application publication number 20130111888A1 discloses a hydraulic circuit. The hydraulic circuit includes a hydraulic swing motor having a first port and a second port. A first motor conduit is connected to the first port of the hydraulic swing motor, and a second motor conduit is connected to the second port of the hydraulic swing motor. The hydraulic circuit further includes a pump to selectively supply a flow of pressurized hydraulic fluid to the hydraulic swing motor through the first and the second motor conduits. A controller is electrically connected to the pump to adjust a torque output of the pump based on a swing speed of the hydraulic swing motor.